Tin plate



l methods. This invention is particularly con-.

' latented Dec. 20, 193 s 2 v I 2,141,110

UNITED" STATES PATENT OFFICE in Drawing. Application November 2 4, 1936,

Serial vNo. 112,609

2 Claims. (C1. 9170.3)

This invention relates to tin plate, one of the mental principle is understood the practice'of the objects being to produce this product so that it invention is an easy matter. If the steel is not will. successfully meet the hydrogen-evolution roughened sufficiently prior to tinning it will be tests used by customers to test its corrosion re- 'found that insuiiicient tin is carried by the trailsistance, regardless of the location of the portion 'ing portion of the plate which, incidentally, is of its surface to which this test is applied. contrary to the troubles encountered in tinning It is to be understood that tin plate consists of hot-rolled steel when the plateis inclined to carry steel coated with tin, and that this steel may be toomuch tin on this portion. Ifth'e surface of produced by either the hot-rolling or cold-rolling the cold-rolled steel is roughened'\too much the same trouble will be experienced as is involved by- 10 cerned with cold-rolled tin plate and-is character the use of hot-rolled steel. It follows that it is ized by. the step-of conditioning the surface of obviously possible to determine when the proper the cold-rolled steelso that when it is passed degree -of roughness has been imparted to the through the tinning' machines its surface carries steel, since the tin will be applied bythe tinning i; sufficient tin into the tinning rolls to permit the machine with substantial uniformity from endlatter to more uniformly distribute the tin over to-end 0r lengthwise of the sheet. the length of the steel. The product resulting from this method pos-.

An example of this conditioning is to slightly sesses greater corrosion resistance than tin plate roughen the surface of the cold-rolled steel, which p du d according to the priortar regardless is normally denser and smoother than the surof Whether'the steel is hot or cold-rolled. As just 29 Uface of the hot-rolled steel. This roughening mentioned, it is impossible to secure uniform dismaybe done by passing the steel throughcoldri ion o the tin in both instances. However, rolls that are slightly rougher than are used for the plate produced according to the present incold-rolling purposes, the roughness of the rolls vention maybe made'to carry its tin with subbeing such that the surface of the cold-rolled i l uniformity over its entire surface area, 25

steel is rougher when it leaves these' rollsthan whereby for agiven W of tin greater 00 cold-rolled steel but is not so rough as hot-rolled rosion protection is secured. steel. The cold-working rolls may be roughened I claim:

forthis purpose by grinding them with an abra- 1'; A method of producing tin plate from cold 30 sive wheel of the proper grit number; also, the rolled steel, including rendering the surface of 30 rolls may be shot-blasted. said steel rougher than normal butnot so rough The described roughening of the cold-rolled as the normal surface of hot rolled steel and substeel may be done during the temper-rolling resequently passing said steel through a tinning 'quired to adjust the stiffness of such steel subsemachine. v e quent to its being annealed to remove the severe 2. A method of producing tin plate from cold 35 hardness induced by the cold-rolling which rolled steel, including passing said steel through brought it to gage. Theother processing required a tinning machine and roughenjng the surface inthe production of the tin plate may be conof said steel prior to passing through said maventional. That is to say, after the steel is .chine to asufficient degree to cause it to carry 40 roughened it may be' cleansed and passed suflicient tin into the tinning rolls of said ma- 40 through a conventional tinning machine where chine to permit the-same to adjust the tin so it is fluxed, dipped into molten tin and passed the coating on the leading parts of said surface through tinning rolls, which adjust and distribute is not substantially greater in thickness than it the tin over its surface. I is on the following parts, said roughening being 1 Some experimentation may be-necessary'to deinsufficient to cause said rolls to adjust said coat- 45 termine the degree of roughening to which the ing so it is thicker on the trailing parts of said steel must be subjected, in view of variations in steel than it is on said leading parts.

' practice. However. once the funda- CHARLES E. 

